\documentclass[UTF8]{ctexart}
\usepackage{enumitem}
\usepackage{tcolorbox}
\usepackage{fontawesome5}
\tcbuselibrary{skins, breakable, theorems}

\newtcbtheorem{note}{\faLightbulb\  注意}%
  {enhanced, breakable,
    colback = white, colframe = cyan, colbacktitle = cyan,
    attach boxed title to top left = {yshift = -2mm, xshift = 5mm},
    boxed title style = {sharp corners},
    fonttitle = \sffamily\bfseries, separator sign = {).~}}{qst}

\begin{document}
\section{测试}

\begin{note}{函数}{example}
已知函数 $ f(x) = (x - 2)\mathrm{e}^{2} + a (x - 1)^{2} $ 有两个零点.
\begin{enumerate}[label=(\arabic*)]
  \item 求 $ a $ 的取值范围;
  \item 设 $ x_{1} $, $ x_{2} $ 是 $ f(x) $ 的两个零点，证明 $ x_{1} + x_{2} < 2 $.
\end{enumerate}
\end{note}

\end{document}